void DecyrptAsyncBackgroundWorker(object sender, DoWorkEventArgs e)
{
DataForDec data = (DataForDec)e.Argument;
byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };
FileStream fsCrypt = new FileStream(data.InputFile, FileMode.Open);
Int32 position = 0;
using (BinaryReader reader = new BinaryReader(fsCrypt))
{
byte prevByte = 0;
byte readByte;
int delimeterSignsCounter = 0;
while (true)
{
readByte = reader.ReadByte();
position++;
if (readByte == 0x3d && prevByte == 0x3d)
{
delimeterSignsCounter++;
if (delimeterSignsCounter >= 52)
{
fsCrypt.Seek(2, SeekOrigin.Current);
break;
}
}
else
{
delimeterSignsCounter = 0;
}
prevByte = readByte;
}
RijndaelManaged AES = new RijndaelManaged();
AES.KeySize = data.KeySize;
AES.BlockSize = data.BlockSize;
if (data.AES_KeyBytes == null)
{
throw new Exception("Key bytes are NULL!!!");
}
var key = new Rfc2898DeriveBytes(data.AES_KeyBytes, saltBytes, 1000);
AES.Key = key.GetBytes(AES.KeySize / 8);
AES.IV = key.GetBytes(AES.BlockSize / 8);
AES.Padding = PaddingMode.Zeros;
AES.Mode = data.CipherMode != CipherMode.OFB ? data.CipherMode : CipherMode.CBC;
CryptoStream cs = new CryptoStream(fsCrypt,
AES.CreateDecryptor(),
CryptoStreamMode.Read);
FileStream fsOut = new FileStream(data.OutputFile, FileMode.Create);
int encryptedData;
long lenStream = fsCrypt.Length;
int prevVal = 0;
sw.Start();
for (long i = 0; (encryptedData = cs.ReadByte()) != -1; i++)
{
fsOut.WriteByte((byte)encryptedData);
if (prevVal != unchecked ((int)(i * 100 / lenStream)))
{
prevVal = unchecked ((int)(i * 100 / lenStream));
backgroundWorker.ReportProgress(prevVal);
}
}
backgroundWorker.ReportProgress(100);
fsOut.Close();
cs.Close();
fsCrypt.Close();
}
}
public DataForDec ReadXml()
{
DataForDec dataForDec = new DataForDec();
string xmlString = "";
try {
using (FileStream fs = new FileStream(data.InputFile, FileMode.Open, FileAccess.Read))
using (StreamReader sw = new StreamReader(fs))
{
string line = "";
while (true)
{
line = sw.ReadLine();
if (line.Equals(delimiter))
{
break;
}
xmlString += line;
}
}
}
catch {
MessageBox.Show("Can not open file input file to decrypted!");
return(dataForDec);
}
using (XmlReader reader
= XmlReader.Create(new StringReader(xmlString)))
{
reader.ReadToFollowing(XmlConstants.KEY_SIZE);
reader.MoveToFirstAttribute();
dataForDec.KeySize = int.Parse(reader.Value);
reader.ReadToFollowing(XmlConstants.BLOCK_SIZE);
reader.MoveToFirstAttribute();
dataForDec.BlockSize = int.Parse(reader.Value);
reader.ReadToFollowing(XmlConstants.CIPHER_MODE);
reader.MoveToFirstAttribute();
dataForDec.StringCipherMode = reader.Value;
reader.ReadToFollowing(XmlConstants.FILE_EXTENSION);
reader.MoveToFirstAttribute();
dataForDec.FileExtension = reader.Value;
string user = "******";
string sesionKey = "...";
while (true)
{
try
{
reader.ReadToFollowing(XmlConstants.USER);
reader.MoveToFirstAttribute();
user = reader.Value;
reader.ReadToFollowing(XmlConstants.SESSION_KEY);
reader.MoveToFirstAttribute();
sesionKey = reader.Value;
if ("".Equals(user) || "".Equals(sesionKey))
{
break;
}
dataForDec.UsersCollection.Add(user, new UserData()
{
EncSesKey = Convert.FromBase64String(sesionKey)
});
}
catch {
break;
}
}
}
return(dataForDec);
}
